Synthesis of overlapping chirp waveforms
AssigneeAAI Corporation
InventorJames R. Cooley
Life of this patent
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Abstract
A digital radar landmass simulator (DRLMS) used for stimulation testing pulse radars, wherein the DRLMS operates by synthesizing time-overlapping chirp waveforms using finite impulse response filters. The DRLMS, thus, effectively generates many overlapping complex pulse signals from many radar reflectors representing a semi-infinite continuum of closely spaced targets. The DRLMS also allows the insertion/injection of the effects of Doppler shift and jamming into the synthesized modulated signal.
Claims45
Apparatus for generating stimulation signals for a pulse radar at an intermediate frequency (IF), thereof, the radar including a receiver, comprising:
- digital means for generating a plurality of simulated surface acoustic waveforms;
- phase locked looped means for providing a timing signal to the receiver;
- and
- first circuit means responsive to said timing means for generating a plurality of modulated synthesized signals.
Apparatus for generating stimulation signals for a pulse radar at an intermediate frequency (IF), thereof, the radar including a receiver, comprising:
- digital means for generating a plurality of simulated surface acoustic waveforms;
- phase locked looped means for providing a timing signal to the receiver;
- first means responsive to said timing means for synthesizing a time-overlapping chirp waveform;
- second means responsive to said timing means for synthesizing a Doppler shifted waveform;
- means for selecting one of said waveforms;
- third means responsive to said timing means for modulating said selected waveform;
- fourth means for filleting said selected modulated synthesized waveform to retrieve a portion thereof;
- and
- mixing means for translating said selected portion of said waveform to said IF.
Apparatus for generating stimulation signals for a pulse radar at an intermediate frequency (IF), thereof, the radar including a receiver, comprising:
- means for accepting radar mode data for producing decision signals;
- timing means phase locked looped to said receiver;
- range bins containing data for a single radar sweep where each said range bin is equal to resolution of said radar;
- means responsive to said timing means for accessing a set of addresses that sequence through all of said range bins at a rate defined by the size of said range bin;
- memory means responsive to said decision signals and said timing means;
- first synthesis means responsive to said timing means and said decision signals for producing time-overlapping chirp waveforms;
- second synthesis means responsive to said timing means for producing a Doppler shifted waveforms;
- means responsive to said decision signals for selecting a waveform from a group consisting of said time-overlapping chirp waveforms and said Doppler shifted waveforms;
- means responsive to said timing means for modulating said selected waveform;
- means responsive to said timing means for filtering said modulated selected waveform to retrieve a portion thereof;
- and
- means responsive to said timing means for translating said portion of said selected waveform to said LF of said receiver.
Method for generating stimulation signals for a pulse radar at an intermediate frequency (IF), thereof, the radar including a receiver, comprising the steps of:
- generating a plurality of simulated surface acoustic waveforms;
- providing a phased locked looped timing signal to the receiver;
- and
- generating a plurality of modulated synthesized signals responsive to said timing signal.
Method for generating stimulation signals for a pulse radar at an intermediate frequency (IF), thereof, the radar including a receiver, comprising the steps of:
- generating plurality of simulated surface acoustic waveforms;
- providing a phase locked looped timing signal to the receiver;
- synthesizing a time-overlapping chirp waveform responsive to said timing signal;
- synthesizing a Doppler shifted waveform responsive to said timing signal;
- selecting one of said waveforms, modulating said selected waveform responsive to said timing signal;
- filtering said selected modulated synthesized waveform to retrieve a portion thereof;
- and
- translating said selected portion of said waveform to said IF.
Method for generating stimulation signals for a pulse radar at an intermediate frequency (IF), thereof, the radar including a receiver, comprising the steps of:
- accepting radar mode data for producing decision signals;
- generating a phase locked looped timing signal for said receiver,
- accessing a set of addresses that sequence through all range bins containing data for a single radar sweep where each said range bin is equal to resolution of said radar at a rate defined by the size of said range bin;
- generating signal strength data from simulated target data and range attenuation data;
- synthesizing time-overlapping chirp waveforms responsive to said timing signal and said decision signals;
- synthesizing Doppler shifted waveforms responsive to said timing signal;
- selecting a waveform from a group consisting of said time-overlapping chirp waveforms and said Doppler shifted waveforms responsive to said decision signals:
- modulating said selected waveform responsive to said timing signal;
- filtering said modulated selected waveform to retrieve a portion thereof responsive to said timing signal;
- and
- translating said portion of said selected waveform to said IF of said receiver responsive to said timing signal.
Dependencies are inferred from the claim text.